JP4702223B2 - Laser optical device - Google Patents

Description

  The present invention relates to a laser optical device, and more particularly to a laser optical device that aligns focused laser light with an optical fiber incident surface.

  A laser optical device transmits laser signal light emitted by a semiconductor laser (hereinafter referred to as LD) and modulated by information to an optical fiber, or transmits laser signal light emitted from the optical fiber to other optical signals. It is an apparatus for transmitting to an optical fiber, and is composed of an optical component such as an LD, a condensing lens for condensing laser signal light from the LD or the optical fiber, and an optical fiber.

  In such a laser optical device, an LD, a condensing lens, etc. must be positioned with high accuracy with respect to an optical fiber having a core diameter of several μm. Usually, these optical components use welding or an adhesive. Fixed.

  However, even if the laser optical apparatus is configured by positioning and fixing the mutual positions of the parts with an adhesive in this way, the following problems remain. First, when a laser optical device is manufactured in this way, the quality of a product can only be determined after being bonded and dried. In addition, it is considered relatively difficult to achieve a high yield with such a laser optical device. Second, it is impossible to correct the performance when there is a change over time. Third, there is a possibility that the fixed position may be shifted due to a temperature change. In particular, when the laser light source is in the vicinity of the optical component, the influence of self-heating of the laser light source is significant.

  Therefore, a configuration of a laser optical device capable of maintaining high performance without being affected by environmental changes including changes in mechanical conditions such as vibration, changes in ambient temperature, changes with time, and the like has been desired and variously studied.

For example, a condensing lens for condensing laser signal light from a laser light source toward an optical fiber, an actuator for moving the condensing lens, and light for detecting the intensity of the laser signal light guided into the optical fiber A detector, an optical deflecting unit that deflects the laser signal light, and a control unit that performs negative feedback control of the output of the optical detector to the optical deflecting unit. A light detector detects a change in the intensity of the laser signal light while wobbling it with a constant period and a constant amplitude in the X direction or the Y direction, and based on the result, the core of the laser signal light in the optical fiber incident surface A technique of an optical communication device that grasps a deviation from the center and controls the laser signal light to be directed toward the center of the core (see Patent Document 1) is known.
JP 2003-338895 A

  By the way, the laser signal light modulated by information such as communication data and image data is required to transmit information accurately without being influenced by the intensity change of the laser signal light due to wobbling or the like.

  However, in the optical communication device disclosed in Patent Document 1, the intensity change of the laser signal light due to wobbling is taken into consideration, and a measure for accurately transmitting information without being affected by the intensity change is suggested. It wasn't.

  The present invention has been made in view of the above problems, and in a laser optical device that aligns a laser signal light modulated and condensed by information with an optical fiber incident surface, accurately transmits information and has high performance. An object of the present invention is to provide a laser optical device capable of maintaining the above.

The above object is achieved by the invention described in any one of 1 to 6 below.

1. A laser beam emitting unit that emits laser signal light modulated by information;
A laser light receiving part for receiving the laser signal light emitted from the laser light emitting part;
A condensing optical unit for guiding the laser signal light emitted from the laser light emitting unit to the laser light receiving unit;
An actuator for moving the condensing optical unit;
An intensity detector that detects the intensity of the laser signal light introduced into the laser beam receiver;
A laser optical device having a control unit that controls driving of the actuator;
The information includes a control signal and a data signal,
The control signal is repeatedly output at a constant period,
The controller is
In synchronism with the control signal included in the laser signal light, the intensity detection unit drives the actuator to reciprocate the condensing optical unit with a minute amplitude during a period when the data signal is not output. A laser optical device that repeats alignment of the laser signal light guided by the condensing optical unit and the laser light receiving unit based on the intensity of the laser signal light detected in step (1) .

2. 2. The laser optical device according to 1 above , wherein the information is communication information or image information .

3. 3. The laser optical apparatus according to 1 or 2, wherein the control signal is a synchronization signal included in the information .

4). The actuator pre Symbol converging optical unit, a laser optical apparatus according to any one of the items 1 to 3, characterized in that moving in two directions perpendicular orthogonal to the optical axis.

5. The control signal is repeatedly output at a constant period,
The controller drives the actuator so that the condensing optical unit performs one-cycle alignment in a period in which the data signal is not output in synchronization with at least two adjacent control signals. 5. The laser optical device according to any one of 1 to 4 , wherein:

6). The actuator includes a piezoelectric element, a vibrating body fixed so as to vibrate with the piezoelectric element, and a moving body frictionally engaged with the vibrating body,
6. The laser optical device according to any one of 1 to 5, wherein the condensing optical unit is mounted on the moving body .

  According to the present invention, the actuator is driven to move the condensing optical unit during a predetermined period synchronized with the predetermined signal included in the laser signal light, and the laser signal light and the laser light receiving unit guided by the condensing optical unit Aligned with. That is, in the case of controlling the laser signal light modulated by information such as communication information and image information so that the laser signal light is directed toward the center of the incident surface of the laser light receiving unit, the communication information and image information The actuator is driven during a predetermined period synchronized with a control signal included in the information such as a start bit, a stop bit, or a synchronization signal. Therefore, the actuator is stopped while a data signal included in communication information, image information, or the like is being output, so the position of the condensing optical unit is fixed. As a result, the data signal can be transmitted accurately without being influenced by the intensity change of the laser signal light caused by the position control operation. Further, since the position control operation is executed without interruption, for example, only while the control signal or the synchronization signal is output, an increase in power consumption can be suppressed.

  The actuator includes a piezoelectric element, a vibrating body fixed so as to vibrate together with the piezoelectric element, and a moving body frictionally engaged with the vibrating body, and a condensing optical unit mounted on the moving body The laser signal light guided by the condensing optical unit and the laser light receiving unit are aligned. That is, since the condensing optical unit is moved by a vibrating body capable of performing minute vibrations, sub-micron order position control is possible with high resolution and high accuracy, and high performance can always be maintained. Further, since the actuator moves the condensing optical unit using frictional engagement, the condensing optical unit can maintain the posture while the energization to the actuator is stopped and the driving is stopped. Therefore, the position of the condensing optical unit can be easily fixed without increasing the power consumption.

  Embodiments of a laser optical device according to the present invention will be described below with reference to the drawings. In addition, although this invention is demonstrated based on embodiment of illustration, this invention is not limited to this embodiment.

  First, the configuration of the laser optical device 1 will be described with reference to FIG. FIG. 1 is a diagram showing an outline of the overall configuration of the laser optical device 1.

  As shown in FIG. 1, the laser optical device 1 includes optical fibers 21 and 22, a condensing optical unit 3, collimator lenses 41 and 42, a half mirror 5, a photodiode 6, a control unit 7, and actuators 8 and 9. Have.

  The optical fibers 21 and 22, the condensing optical unit 3, and the collimator lenses 41 and 42 are arranged on a common optical axis, and the laser light emitted from the optical fiber 21 is incident on the incident surface of the optical fiber 22 by the condensing optical unit 3. It is condensed toward 22a. As described above, the optical fibers 21 and 22 function as a laser beam emitting unit and a laser beam receiving unit in the laser optical device according to the present invention, respectively. Note that an LD may be used instead of the optical fiber 21 as the laser light emitting portion, and an optical waveguide or the like may be used instead of the optical fiber 22 as the laser light receiving portion. For example, in the case of an optical fiber, the size of the incident surface is 10 μm in diameter, and in the case of a waveguide, the size of the incident surface is 2 μm × 1 μm.

  The half mirror 5 reflects a part of the laser beam emitted from the emission surface 22 b of the optical fiber 22 and guides it to the photodiode 6.

  The photodiode 6 corresponds to an intensity detector in the present invention, and detects the intensity of the laser beam guided by the half mirror 5 and converts it into an electric signal.

  The control unit 7 changes the position of the condensing optical unit 3 via the actuators 8 and 9 based on the intensity of the laser light detected by the photodiode 6, and the laser light guided by the condensing optical unit 3 is light. The operation of the actuators 8 and 9 is controlled so as to be directed toward the center in the incident surface 22a of the fiber 22. Details of the control of the actuators 8 and 9 by the control unit will be described later.

  The actuators 8 and 9 are fixed so as to be able to vibrate together with a laminated or roll-type piezoelectric element 811 described later, and the piezoelectric element 811, and a frictional engagement with the driving shaft 812 corresponding to the vibrating body in the present invention and the driving shaft 812. And the converging optical unit 3 mounted on the moving body 814 is moved. The actuator 8 can move the condensing optical unit 3 in one axial direction (X-axis direction) in a plane perpendicular to the optical axis, while the actuator 9 allows the condensing optical unit 3 to move It can be moved in the Y-axis direction orthogonal to the X-axis direction in a plane perpendicular to the optical axis. The configuration of the actuators 8 and 9 will be described later.

  Next, the configuration of the condensing optical unit 3 and the arrangement of the actuators 8 and 9 will be described with reference to FIG. FIG. 2 is a configuration diagram of an XY stage including the condensing optical unit 3 and the actuators 8 and 9.

  As shown in FIG. 2, the condensing optical unit 3 includes a condensing lens 301 and a lens holder 302 for holding the condensing lens 301, and can be moved in the X-axis direction and the Y-axis direction by actuators 8 and 9. It is supported.

  Next, the configuration of the actuators 8 and 9 will be described with reference to FIG. 3A is a configuration diagram of a truss-type actuator provided with a multilayer piezoelectric element, FIG. 3B is a configuration diagram of an element-fixed actuator with a piezoelectric element fixed, and FIG. 3C is a drive shaft. It is a block diagram of the axis | shaft fixed actuator which fixed A. The truss type actuator, the element fixed type actuator, and the shaft fixed type actuator are all known actuators including a vibrating body that vibrates together with the piezoelectric element. In the embodiment of the laser optical device according to the present invention, any actuator provided with such a vibrating body may be used. Here, an outline of the configuration of the element fixed actuator will be described. The details of the element-fixed actuator are disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-185055 “Piezoelectric Conversion Element”, and the detailed description thereof is omitted here. In addition, the configuration of the actuator 9 is the same as that of the actuator 8, and the description thereof is omitted.

  As shown in FIG. 3B, the element-fixed actuator 8 includes a piezoelectric element 811, a drive shaft 812, a weight 813, a moving body 814, and the like, and the weight 8113 is fixed to a housing or the like. A drive signal is input from the control unit 7 to the piezoelectric element 811 that is an energy conversion element to generate minute vibrations, and the drive shaft 812 is vibrated in the direction of arrow A, whereby the moving body 814 that is frictionally engaged with the drive shaft 812. Relative motion is generated by frictional force. Here, the lens holder 302 corresponds to the moving body 814.

  Next, the electric circuit configuration of the laser optical device 1 will be described with reference to FIG. FIG. 4 is an electric circuit block diagram of the laser optical device 1.

  The main electric circuit block of the laser optical device 1 includes an analog signal processing circuit 10, a control unit 7, and the like.

  The analog signal processing circuit 10 converts the current signal detected by the photodiode 6 and converted according to the intensity of the laser light into a voltage signal.

  The control unit 7 includes a low-pass filter 71, an A / D converter 721, an alignment controller 723, a control CPU 72 including an X-PWM 724, a Y-PWM 725, and a drive circuit 73 including an X-amplifier 731, a Y-amplifier 732, and the like. Consists of

  The low pass filter 71 removes high frequency noise superimposed on the voltage signal output from the analog signal processing circuit 10.

  The A / D converter 721 converts the voltage signal output from the low pass filter 71 into a digital signal.

  The alignment controller 723 performs rectangular wave phase detection on the digital signal sampled by the A / D converter 721, and based on the result of the rectangular wave phase detection, 3 of the drive signal (drive pulse) for driving the actuators 8 and 9 is obtained. Two parameters are set: drive frequency, duty ratio, and number of pulses. Details of the rectangular wave phase detection and parameter setting operation performed by the alignment controller 723 will be described later.

  X-PWM 724 and Y-PWM 725 generate drive pulses for driving actuators 8 and 9 in the X-axis direction and Y-axis direction, respectively, based on the three parameters set by alignment controller 723.

  Here, the parameter setting operation performed by the alignment controller 723 and the operations of the X-PWM 724 and the Y-PWM 725 will be described with reference to FIG. FIG. 6A is a diagram showing three parameters, FIG. 6B is a time chart showing drive pulses at the time of forward movement generated based on the set three parameters, and FIG. It is a time chart which shows the drive pulse at the time of reverse produced | generated based on the set three parameters.

  The alignment controller 723 includes a time counter that measures a time (not shown), and sets a threshold TC3 of the time counter based on the digital signal sampled by the A / D converter 721. As shown in FIG. 6A, the time counter is reset at a set threshold value TC3 and repeats the time measurement again. As a result, the timer count waveform exhibits a triangular wave, and the frequency of this triangular wave becomes the frequency of the drive pulse. Next, the alignment controller 723 sets the thresholds TC1 and TC2 of the time counter based on the digital signal sampled by the A / D converter 721. With these threshold values TC1 and TC2, the ON time of the driving pulse at the time of forward movement and the backward movement, that is, the duty ratio is set. Similarly, the alignment controller 723 sets the time ttwc of the time counter based on the digital signal sampled by the A / D converter 721. As a result, the number of drive pulses is set.

  When the threshold values TC3, TC1, TC2, and twc are set by the alignment controller 723 in this way, the X-PWM 724 and Y-PWM 725 are set to the threshold values TC3, TC1 as shown in FIGS. , TC2, and twc, the drive pulses φPWM1 and φPWM2 at the time of forward and reverse are generated at the drive frequency, duty ratio, and number of pulses. FIGS. 6A to 6C are time charts when the set number of pulses is three.

  Returning to FIG. 4, each of the X-amplifier 731 and the Y-amplifier 732 includes the well-known H bridge circuit shown in FIG. 5, amplifies the drive pulses generated by the X-PWM 724 and Y-PWM 725, and 9 is driven.

  In the laser optical device 1 having such a configuration, the control unit 7 detects the intensity of the laser light detected by the photodiode 6, that is, the digital signal sampled by the A / D converter 721, and detects the rectangular wave phase. Based on the result of wave phase detection, the values of three parameters of drive pulses for driving the actuators 8 and 9 are set. Then, the controller 7 drives the actuators 8 and 9 with drive pulses based on the set three parameters, changes the position of the condensing optical unit 3, and the laser light guided by the condensing optical unit 3 is the optical fiber 22. To be directed toward the center of the incident surface 22a. Such a series of operations is hereinafter referred to as “wobbling”.

  Here, the rectangular wave phase detection operation performed by the control unit 7 will be described with reference to FIG. FIG. 7A is a profile in the X-axis direction of the laser light projected on the incident surface 22a to the optical fiber 22, and FIG. 7B is a schematic diagram showing a rectangular wave phase detection operation. The rectangular wave phase detection operation in the Y-axis direction is the same as that in the X-axis direction and will not be described.

For example, as shown in FIG. 7A, the position of the laser beam guided by the condensing optical unit 3 in the incident surface 22a to the optical fiber 22 is X0, and is detected by the photodiode 6 at that time. When the intensity of the laser beam is P0, rectangular wave phase detection is started.
Here, the amplitude of the rectangular wave phase detection is assumed to be two pulses by the drive pulses φPWM1 and φPWM2 shown in FIG.

  First, it stops by moving two pulses in the positive direction. At this time, the position of the laser beam moves from X0 to X1, and the intensity of the laser beam varies from P0 to P1. The A / D converter 721 samples the laser light intensity P1 for a predetermined time, and the alignment controller 723 integrates the sampled laser light intensity P1. The intensity of the integrated laser beam is shown as PI1 in FIG. Next, it moves 4 pulses in the negative direction and stops. At this time, the position of the laser beam moves from X1 to X2, and the intensity of the laser beam varies from P1 to P2. The A / D converter 721 samples the intensity P2 of the laser beam for a predetermined time, and the alignment controller 723 integrates the intensity P2 of the sampled laser beam. The intensity of the integrated laser beam is shown as PI2 in FIG. Next, it moves 2 pulses in the positive direction and stops. Then, the difference between the integrated values PI1 and PI2 obtained at each position is obtained. The difference is shown as ΔPI in FIG. The difference ΔPI obtained in this way is hereinafter referred to as “rectangular wave phase detection output”.

  Here, the rectangular wave phase detection output ΔPI will be described with reference to FIG. 8A shows a profile in the X-axis direction of the laser light projected onto the incident surface 22a of the optical fiber 22, and FIG. 8B shows a rectangular wave phase detection corresponding to the profile shown in FIG. 8A. It is a schematic diagram which shows output (DELTA) PI. As shown in FIG. 8B, the rectangular wave phase detection output ΔPI becomes 0 at the position where the intensity of the laser beam is maximized, that is, the center in the incident surface 22a of the optical fiber 22, and the intensity of the laser beam is maximized. It takes positive and negative values at the left and right of the position.

  Returning to FIG. 7, the rectangular wave phase detection output ΔPI obtained in this way is multiplied by a coefficient (gain) set in advance to obtain a correction amount (correction pulse number), and the calculated correction pulse number. Move. Such operations are repeated so that the rectangular wave phase detection output ΔPI is controlled to approach zero. That is, the laser light guided by the condensing optical unit 3 is controlled so as to be directed toward the center in the incident surface 22 a of the optical fiber 22.

  Next, the flow of the wobbling operation will be described with reference to FIG. 9 and FIG. FIG. 9 is a flowchart showing the flow of the wobbling operation. FIG. 10 is a time chart of the wobbling operation.

  First, the wobbling operation in the X-axis direction is executed. First, the alignment controller 723 sets the number of drive pulses (for example, 2 pulses) in the positive direction (forward direction) for performing the wobbling operation in the period tw1 shown in FIG. The optical unit 3 is moved by two pulses in the positive direction of the X axis (step S1). When the condensing optical unit 3 stops moving and the position of the laser beam on the optical fiber 22 in the incident surface 22a is stabilized, the A / D converter 721 starts sampling (step S2), and the alignment controller 723 Then, the intensity of the laser beam sampled by the A / D converter 721 in the period tw2 is integrated to obtain an integrated value PI1 (step S3). Next, the alignment controller 723 sets the number of drive pulses (for example, 4 pulses) in the negative direction (backward direction) in the period tw3, and causes the condensing optical unit 3 to move 4 pulses in the negative direction of the X axis via the actuator 8. Move by one minute (step S4). When the condensing optical unit 3 stops moving and the position of the laser light in the incident surface 22a on the optical fiber 22 is stabilized, the A / D converter 721 starts sampling in the same manner as in steps S2 and S3. Then (step S5), the alignment controller 723 integrates the intensity of the laser light sampled by the A / D converter 721 in the period tw4, and obtains an integral value PI2 (step S6). Then, the alignment controller 723 sets the number of drive pulses (for example, 2 pulses) in the positive direction (forward direction) in the period tw5, and moves the condensing optical unit 3 by two pulses in the positive direction of the X axis via the actuator 8. Move (step S7).

  In step 4, when the condensing optical unit 3 is moved by 4 pulses in the negative direction (retreat direction) of the X axis, in order to suppress the variation in the drive amount for each pulse during the transition of the rise of the actuator 8. First, it is driven with two pulses, and after stopping once, the remaining two pulses are driven.

  In this way, when the integral values PI1 and PI2 are acquired, the alignment controller 723 subtracts PI2 from the integral value PI1 in the period tw6 to obtain a difference ΔPI (step S8), and whether or not the value of the difference ΔPI is positive. Is determined (step S9). When the value of the difference ΔPI is positive (step S9; Yes), the position where the intensity of the laser light projected onto the incident surface 22a to the optical fiber 22 is maximum is further in the positive direction (forward direction). The controller 723 obtains a correction amount (correction pulse number) in the forward direction (forward direction) by multiplying the difference ΔPI by a coefficient (gain) set in advance in the period tw7, and passes the actuator 8 with the obtained correction pulse number. Then, the condensing optical unit 3 is moved by the correction pulse in the positive direction of the X axis (step S10). On the other hand, when the value of the difference ΔPI is negative in step S9 (step S9; No), the position where the intensity of the laser beam projected onto the incident surface 22a to the optical fiber 22 is maximized is in the negative direction (backward direction). Therefore, the alignment controller 723 calculates the correction amount (correction pulse number) in the negative direction (reverse direction) in the same manner as in step S10, and moves the condensing optical unit 3 via the actuator 8 with the calculated correction pulse number. The correction pulse is moved in the negative direction of the X axis (step S11).

  In this way, when one cycle of the wobbling operation in the X-axis direction is completed in the period twX, the wobbling operation in the Y-axis direction is then performed in the period twY shown in FIG. 10B in the same manner as in steps S1 to S11. One cycle is executed (step S12). Then, the difference ΔPI is 0, that is, the laser beam guided by the condensing optical unit 3 is transmitted through the optical fiber 22 by sequentially repeating such a wobbling operation in the X-axis direction and a wobbling operation in the Y-axis direction. It can be made to go to the center in the entrance plane 22a.

  In the above-described embodiment, the wobbling operation in the X-axis direction and the wobbling operation in the Y-axis direction are switched alternately and repeatedly, but the wobbling operation in the X-axis direction and the wobbling operation in the Y-axis direction are repeated. The frequency may be set so as to satisfy a predetermined relationship and executed simultaneously.

  Specifically, this will be described with reference to FIG. FIG. 11 is a time chart of a wobbling operation according to another example.

Here, when the frequency of the wobbling operation in the X-axis direction is f1, and the frequency of the wobbling operation in the Y-axis direction is f2, f1 and f2 are set to values satisfying the relationship of the following (Expression 1) or (Expression 2). To do.
f1 = 2 × n × f2 (Formula 1)
f2 = 2 × n × f1 (Formula 2)
(In the formula, n is a positive integer.)
Thus, for example, when the frequency f2 of the wobbling operation in the Y-axis direction is twice the frequency f1 of the wobbling operation in the X-axis direction, the wobbling operation in the Y-axis direction is executed as shown in FIG. During this time, the position of the laser beam in the X-axis direction within the incident surface 22a to the optical fiber 22 is held as shown in FIG. Therefore, the intensity of the laser beam does not change. Therefore, the position control of the laser beam in the Y-axis direction can be performed with high accuracy without being affected by the wobbling operation in the X-axis direction. As a result, the wobbling operation in the X-axis direction and the wobbling operation in the Y-axis direction can be performed simultaneously, and the wobbling operation can be speeded up.

  Next, the timing of the wobbling operation performed on the laser signal light modulated by the communication information in the laser optical apparatus 1 having such a configuration will be described with reference to FIG. FIG. 12A shows the timing of an example wobbling operation performed on asynchronous serial communication data, and FIG. 12B shows the example of another wobbling operation performed on asynchronous serial communication data. FIG. 12C is a time chart showing the timing of the wobbling operation performed on the clock synchronous serial communication data.

  First, the timing of a wobbling operation according to an example performed for asynchronous serial communication data will be described with reference to FIG.

  Asynchronous serial communication data SD includes a start bit STB, a data bit (data signal) DTB, a parity bit PTB, and a stop bit SPB, as shown in FIG. A period tw1 for outputting a high level for a predetermined period is provided between the data signal and DTB.

  For the serial communication data SD having such a configuration, a wobbling operation is performed within the period tw1 in synchronization with the start bit STB corresponding to the control signal in the present invention.

  Next, the timing of a wobbling operation according to another example performed for asynchronous serial communication data will be described with reference to FIG.

  Asynchronous serial communication data SD is composed of a start bit STB, a data bit (data signal) DTB, a parity bit PTB, and a stop bit SPB, as shown in FIG. 12B, followed by a predetermined bit following the stop bit SPB. A period tw2 for outputting the High level is provided.

  For the serial communication data SD having such a configuration, a wobbling operation is performed within the period tw2 in synchronization with the stop bit SPB corresponding to the control signal in the present invention.

  Next, the timing of the wobbling operation performed on the clock synchronous serial communication data and the clock will be described with reference to FIG.

  As shown in FIG. 12C, the clock-synchronized serial communication data SD and the clock CLK have a high level for a predetermined period in synchronization with an arbitrary clock CLK1 before the data bit (data signal) DTB is output. An output period tw3 is provided.

  For the serial communication data SD and the clock CLK having such a configuration, a wobbling operation is performed within the period tw3 in synchronization with an arbitrary clock CLK1.

  As described above, in the laser optical device 1 according to the present invention, when the wobbling operation is performed on the laser signal light modulated by the serial communication data, the start bit STB or the stop bit SPB included in the serial communication data SD. Alternatively, the wobbling operation is performed in the periods tw1, tw2, and tw3 that are respectively synchronized with an arbitrary clock CLK1 or the like. Therefore, since the driving of the actuators 8 and 9 is stopped without executing the wobbling operation during the period twD in which the data bit (data signal) DTB included in the serial communication data SD is output, the condensing optical unit is stopped. The position of 3 is fixed. As a result, the data bit (data signal) DTB can be accurately transmitted without being affected by the intensity change of the laser signal light due to the wobbling operation. In addition, since the wobbling operation is performed only within the periods tw1, tw2, and tw3 without being performed without interruption, an increase in power consumption can be suppressed.

  Next, the timing of the wobbling operation performed on the laser signal light modulated by the image information will be described with reference to FIG. FIG. 13A is a timing chart illustrating an example of the wobbling operation performed on the image data, and FIG. 13B is a time chart illustrating the timing of another example of the wobbling operation performed on the image data.

  First, the timing of the wobbling operation according to an example performed on the image data will be described with reference to FIG.

  As shown in FIG. 13A, the wobbling operation is performed within a period tw5 in which the vertical synchronization signal VD is output in synchronization with the vertical synchronization signal VD. Accordingly, during the period twS during which the image signal (data signal) is output, the driving of the actuators 8 and 9 is stopped without executing the wobbling operation, so the position of the condensing optical unit 3 is fixed. Yes. Accordingly, the image signal (data signal) can be accurately transmitted without being affected by the intensity change of the laser signal light due to the wobbling operation. Further, one cycle of the wobbling operation is completed for each frame, and the position of the laser signal light, that is, the intensity is optimized, so that an image signal (data signal) with a good SN ratio can be obtained. The wobbling operation may be performed in the vertical blanking period instead of the vertical synchronization signal VD or in the period in which the horizontal synchronization signal is output.

  Next, the timing of the wobbling operation according to another example performed on the image data will be described with reference to FIG.

  As shown in FIG. 13B, the condensing optical unit 3 is moved in the positive direction, for example, in the first frame and in the negative direction in the second frame in synchronization with the vertical synchronization signal VD. Then, the third frame is moved by a correction amount based on the rectangular wave phase detection output ΔPI obtained by the first frame and the second frame. In this way, for example, the rectangular wave phase detection period can be lengthened by performing one cycle of the wobbling operation over three frames. In this way, the S / N ratio of the rectangular wave phase detection can be improved by performing alignment in one cycle over a plurality of periods.

  As described above, in the laser optical device 1 according to the present invention, in the laser signal light modulated by information such as communication data and image data, the laser signal light is centered in the incident surface 22 a of the optical fiber 22. When the control is performed so as to go, a control signal included in information of communication data or image data, for example, a start bit STB or a stop bit SPB, an arbitrary clock CLK1, a period tw1 synchronized with a vertical synchronization signal VD, etc. The actuators 8 and 9 are driven by tw2, tw3, and tw5. Accordingly, the actuators 8 and 9 are stopped while data signals such as data bits DTB and image signals included in communication data and image data are output. It is fixed. As a result, data signals such as the data bit DTB and the image signal can be transmitted accurately without being affected by the intensity change of the laser signal light due to the wobbling operation. In addition, the wobbling operation is performed without interruption, for example, only during the periods tw1, tw2, tw3, and tw5, so that an increase in power consumption can be suppressed.

  In addition, a piezoelectric element 811, a vibrating body (drive shaft 812) fixed so as to vibrate together with the piezoelectric element 811, and a moving body 814 that is frictionally engaged with the vibrating body are mounted on the moving body 814. The laser signal light guided by the condensing optical unit 3 is controlled so as to be directed toward the center in the incident surface 22a of the optical fiber 22 by using the actuators 8 and 9 for moving the condensing optical unit 3. That is, since the condensing optical unit 3 is moved by a vibrating body (drive shaft 812) capable of performing minute vibrations, position control on the order of submicrons is possible with high resolution and high accuracy, and high performance is always achieved. Can be maintained. Further, since the actuators 8 and 9 move the condensing optical unit 3 using frictional engagement, the condensing optical unit 3 takes an attitude while the energization to the actuators 8 and 9 is stopped and the driving is stopped. Can be maintained. Therefore, the position of the condensing optical unit 3 can be easily fixed without increasing the power consumption.

1 is an overall configuration diagram of a laser optical device according to the present invention. It is a block diagram of the XY stage in the laser optical apparatus which concerns on this invention. It is a block diagram of the actuator in the laser optical apparatus which concerns on this invention. It is an electric circuit block block diagram in the laser optical apparatus which concerns on this invention. It is a schematic diagram which shows the drive circuit structure of the actuator in the laser optical apparatus which concerns on this invention. It is a time chart of the drive signal of the actuator in the laser optical apparatus concerning the present invention. It is a schematic diagram showing a wobbling operation in the laser optical device according to the present invention. It is a schematic diagram which shows the relationship between the laser profile and phase detection output in the laser optical apparatus which concerns on this invention. It is a flowchart which shows the flow of the wobbling operation | movement in the laser optical apparatus which concerns on this invention. It is a time chart of the wobbling operation | movement by an example in the laser optical apparatus based on this invention. It is a time chart of the wobbling operation | movement by another example in the laser optical apparatus based on this invention. It is a time chart of the wobbling operation in serial data. It is a time chart of the wobbling operation | movement in a video signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser optical apparatus 21, 22 Optical fiber 3 Condensing optical unit 301 Condensing lens 302 Lens holder 41, 42 Collimator lens 5 Half mirror 6 Photodiode (PD)
7 Controller 71 Low-pass filter (LPF)
72 Control CPU
721 A / D converter 723 Alignment controller 724, 725 X-PWM, Y-PWM
73 Driving circuit 731 732 X amplifier, Y amplifier 8, 9 Actuator (X axis, Y axis)
811 Piezoelectric element 812 Drive shaft 813 Weight 814 Moving body 10 Analog signal processing circuit

Claims (6)

A laser beam emitting unit that emits laser signal light modulated by information;
A laser light receiving part for receiving the laser signal light emitted from the laser light emitting part;
A condensing optical unit for guiding the laser signal light emitted from the laser light emitting unit to the laser light receiving unit;
An actuator for moving the condensing optical unit;
An intensity detector that detects the intensity of the laser signal light introduced into the laser beam receiver;
A laser optical device having a control unit that controls driving of the actuator;
The information includes a control signal and a data signal,
The control signal is repeatedly output at a constant period,
The controller is
In synchronism with the control signal included in the laser signal light, the intensity detection unit drives the actuator to reciprocate the condensing optical unit with a minute amplitude during a period when the data signal is not output. A laser optical device that repeats alignment of the laser signal light guided by the condensing optical unit and the laser light receiving unit based on the intensity of the laser signal light detected in step (1) .   The laser optical device according to claim 1, wherein the information is communication information or image information.   The laser optical device according to claim 1, wherein the control signal is a synchronization signal included in the information. The actuator laser optical apparatus according to pre-Symbol condensing optical unit, in any one of claims 1 to 3, wherein the moving in two directions perpendicular orthogonal to the optical axis. The control signal is repeatedly output at a constant period,
The controller drives the actuator so that the condensing optical unit performs one-cycle alignment in a period in which the data signal is not output in synchronization with at least two adjacent control signals. The laser optical device according to claim 1, wherein: The actuator includes a piezoelectric element, a vibrating body fixed so as to vibrate with the piezoelectric element, and a moving body frictionally engaged with the vibrating body,
6. The laser optical apparatus according to claim 1, wherein the condensing optical unit is mounted on the moving body.

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